Produced by The Institute for B ird Populations’ Sierra Nevada Bird Observatory Black-backed Woodpecker MIS Surveys on Sierra Nevada National Forests: 2011 Annual Report A report in fulfillment of Forest Service Agreement No. 08-CS-11052005-201, Modification #4. April 19, 2012 Rodney B. Siegel, Morgan W. Tingley, and Robert L. Wilkerson The Institute for Bird Populations P.O. Box 1346 Point Reyes Station, CA 94956 www.birdpop.org Photo by Monica Bond Above: A male Black-backed Woodpecker delivers food to its nest. The Institute for Bird Populations 2011 Black-backed Woodpecker MIS Monitoring Table of Contents Summary........................................................................................................................................ 1 Introduction................................................................................................................................... 5 Methods.......................................................................................................................................... 7 Sample Design ............................................................................................................................ 7 Data Collection ........................................................................................................................... 7 Data Analysis............................................................................................................................ 11 Results .......................................................................................................................................... 19 Scope of Survey Work Completed ........................................................................................... 19 Black-backed Woodpecker Detections..................................................................................... 19 Analysis of Annual Occupancy ................................................................................................ 27 Analysis of Dynamic Occupancy.............................................................................................. 31 Analysis of Multispecies Occupancy........................................................................................ 36 Discussion..................................................................................................................................... 43 Black-backed Woodpecker Annual Occupancy ....................................................................... 43 Black-backed Woodpecker Dynamic Occupancy .................................................................... 44 Multi-species Occupancy within Post-fire Forests ................................................................... 47 Future Directions for this Project.............................................................................................. 49 Acknowledgments ....................................................................................................................... 49 Literature Cited .......................................................................................................................... 50 Appendix I ................................................................................................................................... 54 i The Institute for Bird Populations 2011 Black-backed Woodpecker MIS Monitoring List of Tables Table 1. Encounter history frequencies (numbers of survey points) in the 2011 Black-backed Woodpecker survey data....................................................................................................... 13 Table 2. Summary information for each fire area surveyed once or more during the 2009 – 2011 field seasons of Black-backed Woodpecker MIS monitoring on Sierra Nevada national forests.................................................................................................................................... 20 Table 3. Summary of Black-backed Woodpecker detections and posterior distributions of both fire-level ( ω) and average point-level ( ψ) predictions of occupancy probability for all fire areas surveyed during 2009 - 2011. ...................................................................................... 28 Table 4. Posterior summaries (means and 95% credible intervals) for intercepts and regression coefficients for single-year occupancy models as applied to 2009-2011 survey data.......... 31 Table 5. Top 5 models comparing different combinations of detectability ( p) and occupancy ( ψ0) covariates .............................................................................................................................. 32 Table 6. Top models ( ∆i < 2) comparing different combinations of colonization and extinction covariates .............................................................................................................................. 32 Table 7. Cumulative AIC weights in support of individual covariates in compared models for both colonization and extinction probabilities...................................................................... 33 Table 8. Covariate parameter estimates, standard errors, and significance for the best supported colonization-extinction model .............................................................................................. 34 ii The Institute for Bird Populations 2011 Black-backed Woodpecker MIS Monitoring List of Figures Figure 1. Schematic diagram of our survey methodology for detecting Black-backed Woodpeckers......................................................................................................................... 10 Figure 2. Fire areas on the Modoc and Lassen National Forests that we surveyed for Black- backed Woodpeckers during the 2011 Black-backed Woodpecker MIS monitoring field season.................................................................................................................................... 23 Figure 3. Fire areas on the Plumas, Tahoe, and Eldorado National Forests and the Lake Tahoe Basin Management Unit that we surveyed for Black-backed Woodpeckers during the 2011 Black-backed Woodpecker MIS monitoring field season .................................................... 24 Figure 4. Fire areas on the Stanislaus and Sierra National Forests that were surveyed for Black- backed Woodpeckers during the 2011 Black-backed Woodpecker MIS monitoring field season.................................................................................................................................... 25 Figure 5. Fire areas on the Inyo and Sequoia National Forests that were surveyed for Black- backed Woodpeckers during the 2011 Black-backed Woodpecker MIS monitoring field season.................................................................................................................................... 26 Figure 6. Mean probability of fire-level ( ω) and point-level ( ψ) occupancy for Black-backed Woodpeckers as modeled from individual year-based hierarchical models......................... 27 Figure 7. The modeled relationship between the probability of colonization ( γ), the snag density at a point, and the number of years post-fire ........................................................................ 35 Figure 8. The modeled relationship between fire age and the average cumulative probability of colonization for four levels of snag density.......................................................................... 36 Figure 9. Estimated total richness and richness of nesting guilds by fire age ............................. 37 Figure 10. Modeled relationships between fire age, burn severity, and pre-fire canopy cover and the log of estimated species richness at a point .................................................................... 38 Figure 11. Estimated pooled richness across all survey points of a similar post-fire age and point-specific burn severity class.......................................................................................... 39 Figure 12. Plots of β parameter values for fire age and burn severity covariates for canopy nesting species ...................................................................................................................... 41 Figure 13. Plots of β parameter values for fire age and burn severity covariates for ground and shrub nesting species............................................................................................................. 42 iii The Institute for Bird Populations 2011 Black-backed Woodpecker MIS Monitoring Figure 14. Plots of β parameter values for fire age and burn severity covariates for cavity nesting species................................................................................................................................... 42 iv The Institute for Bird Populations 2011 Black-backed Woodpecker MIS Monitoring Summary The Black-backed Woodpecker ( Picoides arcticus ) was selected by the Pacific Southwest Region of the USDA Forest Service as a Management Indicator Species (MIS) for snags in burned forests across the ten Sierra Nevada national forest units in the Pacific Southwest Region: Eldorado, Inyo, Lassen, Modoc, Plumas, Sequoia, Sierra, Stanislaus, Tahoe, and the Lake Tahoe Basin Management Unit. In 2008 The Institute for Bird Populations collaborated with Region personnel on a pilot study that developed and field-tested survey procedures and collected preliminary information on Black-backed Woodpecker distribution across Sierra Nevada national